轴承内圈沟摆检测的仿真研究与误差分析

为了解决轴承智能生产线工序间在线检测的问题,进行了工序间轴承内圈沟摆自动检测装置的研究;分析影响轴承沟摆检测精度的各种因素,对沟摆检测的误差影响进行了力学分析;采用虚拟样机技术和ADAMS多体动力学仿真软件对轴承的端面跳动量进行仿真。基于设置的仿真参数进行实验验证,实验结果和力学分析结果几乎吻合,证明了检测装置设计的合理性和力学分析的正确性,为轴承内圈智能生产线上沟摆检测装置的设计提供了参考。     

基于ADAMS与MATLAB的数控转塔冲床进给系统联合仿真

本文根据机械多刚体动力学理论,建立数控转塔冲床进给驱动系统的数学模型,利用机械系统动力学分析软件ADAMS建立动力学虚拟样机模型,MATLAB/Simulink建立数控转塔冲床进给驱动伺服控制系统仿真模型,结合两者实现机床的机电联合仿真。通过这种联合仿真,可以分析进给驱动伺服系统的动态特性,为物理样机进给系统的设计与调试提供可靠的参考依据。     

多履带车辆行驶特性分析

根据在多体动力学软件RecurDyn中建立的动力学模型和在多领域建模仿真软件AMESim中建立的液压系统模型,构建多履带车辆的虚拟样机;以液压系统工作压力为分析对象,利用建立的虚拟样机对多履带车辆的直行和转向工况进行仿真,并通过试验进行验证.结果表明:仿真结果与试验数据非常接近,模型具有较高精度,可以为多履带车辆行驶特性的研究提供理论依据.     

基于COSMOSMotion和Excel的牛头刨床动力学分析

应用SolidWorks软件建立了牛头刨床虚拟样机,利用其CAE插件COSMOSMotion对该系统进行运动仿真和动态静力学分析,并利用Excel电子表格的计算功能对仿真结果进行数据处理,得出了系统的等效转动惯量和等效力矩曲线,建立了机械系统的等效动力学模型,最后借助于微分方程的数值求解公式,求解出了牛头刨床在稳定运转阶段的真实运动规律。这种动力学分析方法还可推广至各种复杂机械系统中。     

起-停式定宽压力机刚柔耦合模型的动态仿真分析

为研究起-停式定宽压力机柔性体部件对机械运动精度的影响,分别应用Solid Works和ANSYS软件建立定宽压力机的三维刚体系统模型和侧压连杆的柔性体模型,并在动力学仿真软件ADAMS中采用替换法建立刚柔耦合虚拟样机模型,通过仿真分析,得到了锤头的行程、速度和加速度等运动学参数,侧压连杆与滑架和曲柄之间的接触力分布,侧压连杆的应力及变形情况,并对多刚体和刚柔耦合模型的仿真结果进行了对比,结果可知,刚柔耦合模型更能反映机构的真实运动,为其动态性能的评价和优化提供参考。     

基于多平台虚拟样机模型的轧机压下系统振动研究

为对轧机压下系统振动特征进行仿真分析,提出基于机液耦合的轧机八自由度动力学模型,采用联合建模仿真的方案,在ADAMS建立了符合八自由度动力学关系的轧机机械模型,同时建立基于AMESim的液压位置模型和基于Simulink的闭环控制模型,通过接口互联搭建了压下系统多平台仿真虚拟样机。设计基于带阻滤波器的控制器对干扰造成的虚拟样机耦合谐振进行抑制。仿真结果表明:滤波器的加入能有效抑制耦合振动对虚拟样机系统稳定性和精度的影响。虚拟样机对轧机振动的研究有一定参考价值。     

RV减速器摆线针轮齿廓修形回差影响分析

针对RV减速器回差精度问题,建立了摆线针轮齿廓修形的回差精度数值分析模型,采用几何法求解各种常见修形方式产生的几何回差,同时考虑摆线针轮传动中的弹性回差,推导出摆线轮齿廓修形的回差影响公式,并讨论了同一摆线轮齿廓修形方式下不同的修形参数与同一修形参数下不同的修形方式对回差的影响,得出在同一修形量的条件下,等距加移距的组合修形方式的回差影响最小,移距修形的回差影响最大。对RV-40E型减速器样机进行试验验证,与传统回差公式相比较,文章推导的回差公式精度提高6%左右。     

精密钢球行星减速机构传动分析及仿真

精密钢球行星减速机构是一种高效节能的摆线类传动形式,设计一种二级摆线钢球减速机构,其利用减速钢球作为传动介质,在外摆线槽和内摆线槽构成的循环滚道中进行无间隙啮合传动,分析摆线减速机构的传动原理,对不同类型的减速机构的传动比进行计算。利用动力学仿真软件ADAMS平台,做二级摆线减速机构的运动学模拟仿真,得到运动过程中行星盘和摆线盘的角速度和角加速度曲线,验证分析减速机构的运动平稳性和传动合理性,为二级摆线减速机构的结构优化设计和减速比设计提供理论依据。     

基于虚拟样机技术的数控铣床主传动系统动力学仿真研究

在分析双主轴数控铣床多级齿轮主传动系统运动及受力的基础上,应用ADAMS构建了传动系统的多刚体虚拟样机模型,将Hertz接触理论嵌入仿真模型,实现了齿轮啮合的动态实时仿真,得到了齿轮的动态啮合力,并基于多刚体模型研究了轴线平行度误差对齿轮啮合力的影响.同时利用ANSYS对铣床主轴进行了有限元建模,通过ADAMS建立了传动系统的刚柔耦合虚拟样机模型,分析了主轴在动态下的应力分布.仿真结果为系统传动的平稳性研究和各部件的强度、刚度、疲劳寿命计算提供了参考.     

基于ADAMS和Matlab自平衡双轮电动车系统的联合仿真

运用虚拟样机技术,可以简化机械产品的设计开发过程,缩短产品的开发周期和降低开发成本,获得最优化和创新的设计产品.为了提高自平衡双轮设计的效率与可靠性,本文建立了基于虚拟样机技术的仿真系统.在ADAMS中建立自平衡双轮的动力学模型,首先以倒立摆数学模型为基础,应用拉格朗日方程构造系统的动力学模型,然后通过ADAMS与Ma...     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。